Sony Zeiss FE 24-70mm F/4 ZA OSS | A Kit Lens Upgrade Worth Having?

The standard A7 II kit comes with a pretty good 28-70mm kit lens. It has a variable aperture, but if you know how to work within its limitations, it will be a great performer for you. But there is also a FE 24-70mm F/4 lens on the market, so what should someone getting into the Sony E mount system do?